Section 2 Human Nutrition

Question 1

What elements do carbohydrates contain?

Answer 1

carbon
hydrogen
oxygen

Question 2

What are proteins made of?

Answer 2

amino acids

Question 3

What 2 things make lipids?

Answer 3

fatty acids

glycerol

Question 4

What colour does Benedicts solution go in glucose?

Answer 4

blue - green - yellow - orange - brick red

Question 5

What is used to test for starch?

Answer 5

Put food and a few drops of iodine in a dropping tile.

Starch present: blacky purple colour.
Starch absent: orangey brown colour.

Question 6

What 3 nutrients provide energy?

Answer 6

carbohydrates
fats
proteins

Question 7

Where is calcium found?

Answer 7

milk

cheese

Question 8

What is the function of dietry fibre?

Answer 8

to aid the movement of food through the gut

Question 9

What is a balanced diet?

Answer 9

A diet containing the right amount of each essential nutrients including carbohydrates, protein, lipids, vitamins, minerals, fibre and water.

Question 10

Why do children and teenagers need more energy?

Answer 10

growing

more active

Question 11

What is the equation for energy in food?

Answer 11

energy = mass of water x temperature change of water x 4.2

Question 12

What experiment do you use to find the energy content in a food?

Answer 12

• skewer a crisp of a needle
• add 25cm3 of water to a boiling tube held with a clamp
• measure temperature of water first
• set fire to to food using Bunsen burner
• hold burning food under test tube until food won’t catch fire again.
• measure temperature of water again to get temperature change
• then work out amount of energy in food.

Question 13

What enzyme converts starch into maltose?

Answer 13

amylase

Question 14

What does the enzyme maltase turn maltose into?

Answer 14

glucose

Question 15

Amino acids are formed when protease breaks down ……

Answer 15

protein

Question 16

Where is bile produced and stored?

Answer 16

produced - liver

stored - gall bladder

Question 17

What does bile do?

Answer 17

Emulsify fats.

Neutralises the stomach acid.

Question 18

How do teeth break down food?

Answer 18

mechanically

Question 19

What is the wave of muscle contractions that push food down the gut called?

Answer 19

Peristalsis.

Question 20

why does the stomach produce hydrochloric acid?

Answer 20

to kill bacteria

to give the right PH

Question 21

what does the pancreas produce?

Answer 21

protease
amylase
lipase

Question 22

what is absorbed in the large intestine?

Answer 22

excess water

Question 23

what are the five steps of the digestive process?

Answer 23

Ingestion
Digestion
Absorption
Assimilation
Egestion

Question 24

what is assimilation?

Answer 24

when digested molecules become part of the cells

Question 25

Describe the structure of a villus and how villi help with absorption.

Answer 25

Line the small intestines wall and stick out. Contain blood capillaries and are covered in epithelial cells.

They help the small intestine have a bigger surface area.
They also contain blood capillaries to carry away absorbed food molecules.

Question 26

Energy requirements vary with…

Answer 26

Activity levels,
Age,
Pregnancy.

Question 27

Where are carbohydrates found and what is their function?

Answer 27

Bread, pasta, rice, potatoes.

A source of energy.

Question 28

Where is protein found and what is its function?

Answer 28

Meat, fish, eggs, dairy.

Strength for muscles.

Question 29

Where are lipids found and what is their function?

Answer 29

Butter, crisps, chips.

For storing of energy.

Question 30

What is used to test for glucose?

Answer 30

Put food and a few drops of benedicts solution in a test tube.
Heat in a beaker of hot water.

Glucose present: Orange precipitate colour.
Glucose absent: stays blue colour.

Question 31

What is used to test for protein?

Answer 31

Put food and a few drops of dilute sodium hydroxide in a test tube.
Add the same amount of dilute copper sulphate.

Protein present: lilac colour.
Protein absent: stays blue colour.

Question 32

What is used to test for lipids?

Answer 32

Put food and ethanol in a test tube and shake.
Put water in another test tube and add food and ethanol to test tube with water.

Lipids present: milky white layer.
Lipids absent: stays clear.

Question 33

What organs are in the human alimentary canal and what are their functions?

Answer 33

Mouth: mixes food and saliva.

Oesophagus: has a muscle around it which contracts in waves to push food down (peristalsis).

Stomach: makes digestive juices that contain proteases. These start the digestion of protein to amino acids.

Pancreas: creates insulin hormone that tells liver to take glucose out of your blood.

Small intestine: squeezes liquid food down large intestine.

Large intestine: water can be absorbed into the blood here.

Question 34

Describe the processes of ingestion, digestion, absorption, assimilation and egestion.

Answer 34

Ingestion: the consumption of a substance by an organism.

Digestion: the breakdown of food into smaller components that can be absorbed into the bloodstream.

Absorption: when digested food molecules pass through the wall of the small intestine and into our bloodstream.

Assimilation: the movement of digested food molecules into the cells of the body where they are used.

Egestion: getting rid of un-digested food from the gut.

Question 35

Fatty acids and glycerol are formed when when lipases break down…

Answer 35

Lipids.

Question 36

Enzymes are…

Answer 36

Biological catalysts in metabolic reactions.

Question 37

How can the functioning of enzymes be affected?

Answer 37

Changes in temperature.

Changes in pH.

Question 38

How does heat / temperature affect enzymes activity?

Answer 38

Higher temperatures increase the rate of enzyme activity until at optimum, then the enzyme denatures.

Question 39

Hi

Answer 39

Bye

Question 40

Hey yo

Answer 40

Bye yo